Date Published: January 30, 2019
Publisher: Public Library of Science
Author(s): Yaojie Yue, Lan Zhou, A-xing Zhu, Xinyue Ye, Suzannah Rutherford.
This paper establishes the quantitative relationships between hail fall parameters and crop damages by examining the impacts of 49 hail hazard scenarios on cotton in the bud stage and boll stage. This study utilizes simulated cotton hail hazard to analyze the following data: hail size, hail fall density, and crop damages (i.e., defoliation rate, branch breaking rate, and the fruit falling rate). The results are as follows: 1) cotton vulnerability increased via an increase in crop damages as the hail hazard magnitude increased; 2) crop damages exhibit significant logistic relationships with hail diameter and hail fall density, and the fit was better at the bud stage than at the boll stage; 3) cotton is more vulnerable to hail hazard at the bud stage than at the boll stage, and the bud stage is a critical period for cotton hail disaster prevention and mitigation; and 4) damages to cotton plant at the bud stage and boll stage were less sensitive to hail size from hail fall density. Thus, we suggest that hail diameter can be used as the priority indicator to predict hail-induced crop damages. These results provide a sound basis for developing a comprehensive evaluation of hail damage in cotton, which is crucial for promoting sustainable cotton production. We recommend that the impacts of hail-induced crop damages on yield and fiber quality need to be addressed further in future studies.
It has been reported that the total number of severe weather events, including hail, decreased significantly throughout most of China over the past and recent decades [1–4]. Fewer hail days are expected over most areas of the US in the future . However, damage from hailstorms may increase in frequency and severity with global warming [6, 7], which may cause a shift toward the more frequent occurrence of larger hail . Crops are highly vulnerable to hail strike, and hail can induce severe agricultural losses [1, 8–14]. Therefore, vulnerability analyses of crops subjected to hail falls is an essential step for reducing the consequences of hail events . Analyzing the impact of hail falls on vulnerable crops is a crucial scientific issue for promoting sustainable agriculture, given the trend of increasing hailstorms. However, there are few well-established procedures for such an analysis in China and around the world.
In this paper, the vulnerability of cotton to hail is defined as the quantitative relationship of damage to cotton leaves, branches, buds, and bolls by corresponding hail hazard intensity, that is, the focus is on assessing the damage to cotton morphology. The impact of hail-induced damages on cotton yields was also observed in our study, and these results will be presented in a future paper.
Determining cotton vulnerability to hail hazard is a key scientific issue for hail disaster mitigation in China and across the world. This paper aims to reveal the effects of hail parameters on crop damages via field experiments. The following conclusions can be drawn.