Beijing, China
May 06, 2011
Currently, in southwestern China the major part of corn crops is at the stage of seedling emergence to four-leaf growing while in mountainous areas and plateaus there corn is just being sowed. In general, corn crops have a higher ratio of seedling emergence and a good growing condition thanks to sufficient soil moisture up to now this year. However, due to continuous lower temperature and sudden drop or rise in temperatures in this region, the sowing time of spring corn has been put off. To ensure full emergence, uniform growth and stronger seedlings for good harvest, a corn expert group organized by the Ministry of Agriculture (MOA) has made its opinions on field management during the growing period of corn seedlings in the region as follows:
Interplanting. It is required for a better management of fertilizer, water and pest control during the seedling growing period. At the second stage of this period, for a balanced growth, it is suggested to apply 10 kg of urea plus 6% of potassium dihydrogen phosphate as additional fertilizer deeply at the two sides of each row with focus on small and weak seedlings.
Plastic film covering. It is suggested thatthe coverings take off in right time according to the temperature and seedling emergence, avoiding damages to the seedlings from high temperature; seedling holes be covered with soil to give full play of plastic film for keeping temperature and moisture, and control of weeds; and apply additional fertilizer by means of sprayer and subsoil application device. It is required for standardized operations to reduce damages to and prolong use time of plastic film.
Direct sowing. In the case of direct sowing, it is required to check seedlings in a time manner. Should rotten seeds or dead seedlings be detected, it is necessary to resow or replant as early as possible, and bank up with soil for early sprouting and seedling emergence. For fields of dense seedlings, plant thinning must be performed at the three-leaf stage. At this stage, it is proper to keep seedling density with 110% of the planned one. At the five-leaf stage, the final thinning of seedlings should be up to the planned density.
In addition, due to an earlier raining season this year, it is suggested that gutter- or hole-fertilizer could be put five days earlier than normal years to those fields with no or insufficient basal fertilizer applied. In such a case, the amount of fertilizers to be applied should be as much as the planned total of basal fertilizer and that for seedling growth.
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