Effects of Plant Population, Cultivar and Hail Damage on Maize Yield. Article Sample.

The research was based on three factors that affect the maize yield which included crop population, cultivar and hail damage. Experiments were numbered and conducted on all three factors.

Chapter One

The chapter reviews the literature and the background information on the study, the problem statement presentation, research questions, aim, and objectives. The study was conducted using two approaches which are; a participatory survey where random participants were selected randomly in three locations using questionnaires to scrutinize the locals knowledge of maize production, popular varieties and hail damage in maize. The second was a field trial experiment conducted during a maize growing season at three sites of different bioresource characteristics to determine maize performance in relation to planting density and reproduced hail damage.

The literature reviewed was of previously written works related to the research study. Review work revealed that just like rice and wheat, maize remains a staple food for many around the globe. Factors that determine maize yield include genotype, crop management, and environmental conditions. According to the research, a hailstorm is one of the natural hazards that affect crop yield.

Factors that influence attenuation of light by a maize crop can be explained regarding leaf size, shape, and orientation which are affected by genotype (cultivar or hybrid) as well as crop management practices and environmental conditions (Lizaso, Batchelor, Boote, and Westgate, 2012). Research recognizes that there is limited information about the interaction between environmental and genetic controls on maize plant population with previous studies using simulation models to understand their relationship. Maize hybrid differs in plant height, leaf number, individual leaf area, vertical leaf angle and leaf area density distribution along the main stem. As the plant population increases maize yield potential increases, but due to competition, there is a level at which the maize yield will decrease. The competition is for resources such as light, water, and nutrients.

Cultivars are cultivated varieties that are either propagated by seeds or vegetative material; they are a variation of species that have been produced through breeding or deliberate selection. Maize cultivars tend to differ in a diversity of environmental conditions; they vary from one another due to their different genetic assortment of inbred characteristics. A reason as to why cultivars have their peculiar adaptability and yield potential (Jackson and Craig, 2013). However, it is not necessary that cultivars be chosen strictly from a particular piece of land or bioresource conditions since maize can be grown in extensive, diversified conditions. It is therefore important that cultivars possessing a wide adaptability capability be used to stabilize yields under the changing weather conditions in each maize growing country. The importance of maize cultivars trial was conducted in KwaZulu-Natal in South Africa in the major grain producing areas where fifty cultivars were evaluated. The results of this study showed that poor management and inaccessible resources by small-scale farmers led them to attain a 50% less yield than that attained by commercial farmers in accordance with cultivar selection decisions (Arathoon and Mtumtum, 2013).

Hail is defined as a precipitation of ice water from the clouds to the ground which is a summer related weather condition that affects maize also being a summer crop. Hail damage simulation, on the other hand, is an experiment to study its effects on maize yield using a systematic mature leaf-tearing method. Yield loss from hail damage is based on the reduction in plant population and leaf area of the maize crop. The effects of such problems differ with severity and duration of the attack and the stag of crop development at the time of the attack (Vorst, 1990). According to the research conducted on the effects of a hail storm in maize yield, maize is most sensitive to this attack from the full canopy cover to the grain development stage where the greater the leaf area damaged, the higher the risk of yield loss. When attacked at early stages of development, young leaves may recover speedily as they are being substituted by new leaves occasionally (Nielsen, 2013). Hailed maize usually achieves an early physiological maturity but take longer to dry-down that their non-hailed counterparts.

The success of maize production largely depends on factors such as production resources, plant population, adapted cultivars, crop management, other detrimental conditions like hail and stress, and marketing of the end product. These factors are the most common ones that largely impact maize production even though they are not the only ones to be considered (Plessiss, 2012). Maize performance is highly influenced by genotype, bioresource area and management practices which cannot be separated even though there is no clear evidence on the interactive effects of these factors.

Problem statement

It is unrealistic to fully predict and control all edaphic factors even under controlled environment studies since maize growth and yield is influenced by both edaphic and management factors. Planting density is one of the factors that are hard to generalize since it depends on cultivar and environment. The negative effects of hail which is unpredictable can be lessened by manipulating the planting density. Arguably, because of the intercrop density, crops with high planting density will have difficulty recovering from hail compared to crops with adequate space and availability of nutrients after a hail damage. Much research on this subject needs to be done on maize as a major staple food to advice farmers who produce maize under hail prone conditions. No substantive research have been done in KwaZulu-Natal or South Africa on the effects of hail damage on maize at different stages of crop development on dry land conditions to advice small-scale farmers. The research is very important for the small-scale farmers to expand their knowledge on crop management with regards to hail damage since there is no insurance coverage for hail damage.

In plant population, the primary rationale for narrow-row spacing in maize is that by reducing overcrowding of crops in a row will provide them with adequate light, water, and nutrients and reduce competition. Successful maize production depends on the correct application of inputs that will sustain the environment as well as the agricultural production. Research shows that factors do interact on how they affect maize yield. Use of narrow-rows on different landscape positions of a field could reduce maize yield.

Genetic improvements in hybrids over the years have led to a rise in maize yields. The best grain-producing hybrids in a particular area are usually the best adapted to the local growing conditions and are therefore likely to be the best silage producing hybrids. In areas where hail is an unpredicted occurrence, crops planted at a high planting density will have a hard time recovering from hail damage because of intercrop competition as compared to crops with space availability and nutrients availability. The information can be beneficial when advising farmers on preventive measures against hail damage.

Research question, hypothesis, and specific objectives

The primary research question of this study was whether there is any relationship between maize cultivar, and plant population concerning response to 80% simulated hail damage. The secondary question in this study was whether there is a genotype by environment interaction with regard to this response. These questions were considered in a broad aim to determine the effect of hail damage on three maize cultivars planted at three populations at three bioresource areas of KwaZulu-Natal. Another aim of the study was to evaluate the knowledge of smallholder farmers of the Zululand District in KwaZulu-Natal about maize production and management of hail damage. The hypothesis of the study was that hail damage decreases maize yield regardless of the stage of development of the crop. The locals of Zululand had no idea on how to manage their maize crops as far as hail damage was concerned.

The specific objectives of the study were to determine the effect of simulated hail damage in relation to plant population and stage development and determine their interaction with respect to response to hail damage. The other objective was to determine the maize genotype x environment interaction with respect to response to hail damage.

Chapter Two

The methods and procedures followed by the researcher were to evaluate the effect of seeding rate in maize field trials, cultivar types and the hail damage. On maize grain yields (Nielsen et al, 2012). There were three popular cultivars of white maize that were used for the cultivar experiment with hail damage simulation experiment being conducted at three levels of plant vegetative growth.

A participatory survey was used to investigate the local knowledge about plant population, cultivar choice and hail damage in maize and other supplementary crops like beans and vegetables. A survey questionnaire method was used in this particular study during the 2013/2014 maize planting season to evaluate the opinions, feelings, and perception of locals about this topic and possible reduction. There were predetermined questions where the respondents were required to fill in and be able to give their answers and obtain perception and views of particular groups (Tharenou et al., 2008). Samples from about 6o or more farmers were derived from the three districts, and the results analyzed using linear regression model Strata statistical software version 11 and appeared as appendices.

The study was designed to get information about the effects of plant population, cultivars and hail damage on maize yield in KwaCeza, KwaDube and Ulundi districts. Experiments conducted at the three different selected sites in these districts were replicated (3) three times in an (RCB) Randomised Complete Block design with a factorial arrangement with a plot size of 3 x 3.5m. A 3x3x3 m factorial experiment with 27 plots and a total of 81 plots in each site for the experiment was used with the designs being used to evaluate three factors simultaneously. Three different maize cultivars; SC7701, PAN53 and SAHARA, were planted at three different sites to identify the effects of spacing, cultivars and hail damage on maize yield. Flowering stage is the most crucial stage in the development of corn from the perspective of grain yield determination (Goss, 2008). The stress related to temperature, drought, pests and hail damage have a greater potential of affecting maize yield especially when they occur at the reproduction stage. Maize cultivars are divided into three categories modified into various breeds that can survive in different ecological conditions. Statistics reveal that numerous cultivars of maize have been developed and adopted across the globe with some doing well in highlands areas while others flourish in the semi-arid regions with low rainfall levels. Research shows that exotic breeds of maize can produce better yields than their indigenous counterparts.

The records kept included trial activities plus other times, records of each product used; seeds, fertilizers, and soil analysis results for each site. All treatments were planted using the approved fertilizers after soil sampling recommendations. The 8kg N and 1kg P were applied as per the target yield of 12t/ha and ploughed in, 10kg of superphosphate mixed with 5kg LAN was broadcast in the planting area and worked into the soil with a hand hoe. Finally, 25kg LAN was applied as top dressing 4 weeks after the planting took place. The land was ploughed tw...