Effects of moisture content and fertilizer source on growth and yield of sweet corn

Corn (Zea mays L.) is one of the most important cereal crops worldwide, next to wheat and rice. In Malaysia, corn can grow successfully as the climate of the country is suitable for the crop. However, it is a minor crop even though the demand for corn increases over the years. Corn is imported yearly to satisfy the country’s needs. The main challenges for corn production are low soil fertility, low pH and water shortage. Thus, to overcome these problems, two studies were conducted in a rain shelter at Field 2, Faculty of Agriculture,Universiti Putra Malaysia, Serdang, Malaysia. The objectives of first experiment were to determine the effect of soil moiture content and fertilizer sources on the growth and yield of sweet corn and to evaluate the effect of their interaction on the yield of the sweet corn. The treatments were four soil moiture contents (Smc) namely: 100% (Smc1), 90% (Smc2), 80% (Smc3), and 70% (Smc4), and four fertilizer sources namely: mineral fertilizer (NPK), goat manure (GM), poultry manure (PM) and without fertilizer (control). The treatments were arranged in split-plot design as the moisture content was assigned as main plot factor while fertilizer sources as sub plot factor. The results showed that the total dry matter (all above ground excluding yield) significantly (P<0.05) increased with the increase in soil moisture content. 100% soil moisture content (Smc1)) with goat manure (GM) gave higher biomass compared to PM and control treatment. Highest root dry weight was achieved from 90% soil moisture content (Smc2) with poulry manure (PM). In terms of yield components, interaction between soil moisture content and fertilizer sources significantly (P<0.05) affected the plant cob and ear weight. Both organic ( GM and PM) and inorganic (NPK) fertilizers enhanced cob and ear weight at Smc1 and Smc2 while NPK and GM gave higher grain weight at Smc1and Smc2 compared to PM and control treaments. Positive correlation between total dry matter, yield components and nutrient uptake was observed, indicating better crop response to soil moisture and fertilizer (organic and inorganic) application. The second experiment was conducted in Field 2 under rain shelter to evaluate the effect of soil moisture contents and inorganic fertilizer levels on the growth and yield performance of sweet corn and to determine the maximum NPK rate that would enhance high growth and yield of sweet corn. Three soil moisture contents and four fertilizer levels were used namely: 90% (Smc2), 80% (Smc3) and 70% (Smc4), while NPK fertilizer levels were: F1 (0:0:0 kg ha-1), F2 (60:30:45 kg ha-1), F3 (120:60:90 kg ha-1) and F4 (180:90:135 kg ha-1). The results showed that total dry matter yield significantly (P<0.05) increased with increase in soil moisture content. 90% (Smc2) treatments with 150% (F4) gave higher shoot dry weight compared to the other fertilizer levels. Soil moisture contents and fertilizer levels significantly (P