1) What is the range of temperature sensitivity for Corn?
Metabolic activities are affected at temperature > 40 Co and < 10 Co
2) Can anyone use a seed treatment?
Improper seed treatment affects seed germination and seedling because seed is sensitive to chemicals. Dealers and farmers should be educated and knowledgeable about proper seed treatment techniques and handling before use.
3) How do long and hot days impact growth?
Continuous heat, drought or any stress affects plant growth. Long and hot periods lasting for more than 24 hours disturb plant cycles and photosynthesis (food making process) which ultimately affects yield.
4) How do long and hot nights impact growth?
Long, hot nights cause the plant to go through photorespiration that causes loss of energy and affects plant growth. The plant uses its energy to defend its system, therefore after photorespiration there is no energy left to run the plant metabolism.
5) What are other factors (other than heat) dangerous for pollination?
• Very low (<20%) humidity
• Very high (>80%) humidity
• Moisture stress
• Nutrient stress (specially nitrogen)
• Long duration of rain and continuous wind storms
• Silk and pollen timing difference.
6) What are the factors favorable for pollination?
• Even germination
• Sufficient nutrients
• Soil water availability during pollination
• Optimum temperature: 30-38 Co
• Relative humidity: 30%-50%.
7) What are basic criteria for balancing fertilizer?
NPK 1:0.5:1 or depending on soil test
8)What is the criteria for the most suitable land for corn planting?
Well drained loose soils and soils where vegetables can be planted are generally good for corn.
9) What are the best stages/timing for irrigation?
• The soil surface should not remain dry for good corn yields
• Corn should be irrigated frequently during all stages of growth especially from flowering to physiological maturity (black layer).
10) What are the best stages/timing for fertilizer application?
• Before planting: total Phosphorus and Potash fertilizer as basal dose (This line should be 1st line)
• Growth stages (V6, v10, v14, tasseling)
11) What is the Impact of weeds on yield?
It depends on the weed pressure, generally weeds make 20%-30% loss especially in the early 30 days when the crop is young.
12.) What is the difference between heat & drought resistance, which is more important for Pakistan?
When there is heat, the plant is affected by drought. Plant systems do not work effectively in heat >38 Co and It is difficult to separate both.
13) Can we calculate the losses due to early harvesting?
It will be difficult to calculate precisely, but early harvesting will cause the grain to weigh less because it is not fully developed.
14) What are the most critical stages for frost & what is the impact of frost?
Just after germination to V5 stage. In this period leaves may die, become yellow, brown and no growth. Plant will recover before V5 stage when growing point is below soil.
15) What are the best methods for corn grain storages, you can suggest to farmers?
• Shelled corn - dry grain at below 13% moisture
• Unshelled cobs can be stored if dry at 20% moisture
• Keep in a well aerated place
• Avoid excessive moisture and humidity.
16) Which pest is most dangerous for corn?
Shoot fly, stem borer, armyworm and ear worm, all can reduce corn yield.
17) What is the future of corn?
There is a huge demand for corn in Pakistan. Corn is used in poultry feed, wet milling, silage, green cobs and animal feed.
18) How many days are taken by Corn seed to germinate?
Answer: It depends upon temperature, generally spring corn germinates within 10-20 days and autumn corn germinates within 4-6 days.
19) Is there any difference of corn yield between small seed vs large seed size?
Ans: There is no difference in corn yield due to seed size.
20) What factors affect seed setting?
• High temperature (>40 C )
• High humidity
• Water stress
• Nutrient deficiency
• Continuous rainfall
21) When I should harvest my Corn crop?
Answer:Corn crop should be harvested at physiological maturity (Black layer)
22) At what crop stage Corn crop can be harvested for silage?
Answer: Corn crop should be harvested for silage at R4 to R5 stage (60-70% moisture)
23) What factors may cause disease incidence in Corn?
• Lack of balance fertilizer
• Susceptible environment (temperature & humidity)
• Presence of disease pathogen