Legume Genomics and Genetics 2025, Vol.16, No.6, 297-312 http://cropscipublisher.com/index.php/lgg 304 The secondary disasters caused by continuous rain are mainly diseases, followed by insect pests. In the pea-wheat rotation system, the delayed wheat sowing date caused by continuous rain may also increase the base number of pea rust sources in the next season, making the pea disease more severe. In terms of countermeasures, it is necessary to strengthen the prediction, early warning and timely prevention and control of diseases during continuous rain. The meteorological department cooperates with the plant protection department to organize pesticide application during the weather window before and after continuous rain, which can effectively control the spread of diseases. For example, the Hunan region has carried out rapeseed sclerotinia control in the intervals between rainy days, successfully controlling the disease to a light level. Similar measures should also be used in pea production. When there is a slight break in continuous rain, broad-spectrum fungicides should be sprayed in time to prevent further threats to pod formation. At the same time, after continuous rain, the diseased remains in the field should be cleaned up to destroy the places where pathogens survive summer and winter, so as to prevent the return of diseases and pests in the next season. 5.2 Disruption of fertilization and field management schedules Agricultural production requires timely field management, but continuous rainy weather often disrupts the normal rhythm of farming. First, the sowing and harvesting periods are affected: if continuous rain occurs during the pea sowing period, the fields are muddy and seeds cannot be sown. Missing the appropriate sowing period will lead to slow growth and delayed maturity in the seedling stage, and ultimately reduce yields. In autumn, continuous rain may affect the harvest of the previous crop, thereby delaying the sowing of peas (Zhang et al., 2020). If peas are delayed in sowing and miss the best growing season, they are prone to adverse conditions such as high temperature and drought in the later period, resulting in reduced yields. Secondly, it is difficult to carry out management measures such as topdressing and pesticide application in time. Continuous rainfall causes water accumulation in the fields, and machinery and manpower cannot go to the fields to apply fertilizers; even if chemical fertilizers are spread, they are easily leached or volatilized by rain, which greatly reduces the fertilizer efficiency. Continuous rain will also affect the effect of foliar fertilization and plant protection. It is impossible to spray foliar fertilizers and pesticides when it rains all the time, and the window period for pest and disease control is missed. When remedial measures are taken after the rain, the crops may have suffered irreversible damage. Continuous rain causes the soil to be too wet, and "farming during the rain" can easily cause soil compaction, and some agricultural operations can only be delayed. For example, in the early rice seedling raising in the south, if there is continuous rain and low temperature, the seedling raising will be delayed, and the quality of the seedlings will deteriorate; too long seedling age will affect the tillering of the field. For peas, too late planting or too late topdressing is not conducive to pod formation. The survey shows that the inadequate field management during the critical growth period of peas caused by rain is one of the important reasons for the reduction in production. For example, farmers in the mountainous areas of Guizhou reported that it rained for three consecutive weeks in the spring of a certain year, and weeding and soiling work in the pea fields could not be carried out at all. As a result, weeds grew, plants fell over, and the number of pods decreased by nearly 40%. Therefore, the interference of continuous rain on agricultural arrangements cannot be ignored. In terms of response strategies, some flexible measures can be adopted: for example, the application of slow-release fertilizers to reduce the impact of rain erosion; rush to apply base fertilizer before the rain, and apply topdressing in time after the rain; promote protective tillage to avoid soil compaction due to rain; use rain-resistant mechanical equipment (such as light plant protection drones) to operate under wetland conditions, etc. There should be a management idea of "taking advantage of every opportunity" to complete key agricultural work in the intervals between rainy days to minimize the losses caused by weather delays. 5.3 Poor field ventilation leading to crop crowding During the continuous rainy period, due to insufficient sunshine and high air humidity, the microclimate in the pea field becomes stuffy and unventilated, which is prone to group closure. This closed environment will in turn aggravate the trend of declining pod setting rate. Specifically, when it rains continuously, the wind speed over the farmland is low and the humidity is high. The transpiration of the leaves in the pea canopy is suppressed, and the
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