The Latest Methods to Increase Tillering Rate in Rice at the Seedling Stage
Apply tiller-promoting fertilizer early and tiller-preserving fertilizer sparingly
Nitrogen nutrition plays a leading role in rice tillering. The amount of fertilizer applied during the rice tillering stage is 25-30% of the whole growth period, so applying quick-acting nitrogen tiller-promoting fertilizer early, so that the leaf color quickly turns dark green, is the main measure for promoting early tillering. Early-maturing varieties have a short tillering stage, and the tiller-promoting fertilizer must be applied all at once within 7-10 days after transplanting. For medium- and late-maturing varieties, the tiller-promoting fertilizer is generally applied about 15 days after transplanting. By the end of the effective tillering stage, if the number of effective stems is obviously less than the expected suitable number of panicles, a moderate amount of tiller-preserving fertilizer should be applied to promote steady tiller growth.
One-cun water to establish the seedlings, shallow water to revive them
When transplanting rice, thin water is generally used for transplanting to facilitate shallow planting. After transplanting, the water layer should be appropriately deepened to reduce evaporation from the leaf surface and lessen transplanting injury, so as to help the seedlings turn green and survive. However, it should not be too deep, lest the lower leaves be drowned and the water temperature be lowered, affecting root development. Generally, 1-1.5 cun is suitable, which is what is meant by “one-cun water to establish the seedlings.” After the seedlings turn green, the water layer should immediately be lowered to 0.5-1.0 cun to favor tillering and root development. This is because the occurrence of tillers and the growth of the root system are closely related to temperature. During the tillering stage, shallow irrigation is required, but water must never be cut off and the plants must not suffer drought; shallow water and frequent irrigation must be practiced.
Careful weeding, timely field drying
After the seedlings revive, herbicide can be applied for weed control. To control barnyardgrass and broadleaf weeds: use 150-200 grams per hectare of butachlor + bensulfuron-methyl or pyrazosulfuron-ethyl; to control barnyardgrass older than three leaves and triangular bulrush: use 500 grams per hectare of 50% quizalofop-p-ethyl + 2 kg of bentazone, mixed with 300 kg of water for spraying. This can achieve the weed-killing effect. At the late tillering stage of rice, the field should be dried at the appropriate time. The timing of field drying is very important. First, look at the tillering situation and practice “dry the field when there are enough seedlings”; second, look at the growth vigor of the rice plants. If growth is vigorous, leaf color is deep, and there is a tendency to excessive growth, dry early and dry heavily; if growth is slow and leaf color is relatively light, dry later and dry lightly; third, look at the soil conditions. Fields with rotten soil and deep mud foot should be dried early and heavily. For low-lying fields and cold-waterlogged fields, even if the rice plants are not growing vigorously and there are not enough tillers, drainage should still be carried out early and the field dried lightly. After field drying, saline-alkali land is prone to salt accumulation, and newly opened rice fields with poor water retention will suffer aggravated seepage after field drying. In addition, in some cold regions, the method of “deep water to submerge tillers” can be used to inhibit late tillering. The depth should preferably be about 10 cm, and the time should not be too long, generally no more than 10 days, so as to avoid excessive elongation of the basal internodes, which can easily cause lodging.