Physiological plant disorder diseases. Improving drainage will help to alleviate this problem. Hail can cause damage to soft skinned fruits, and may also allow brown rot or other fungi to penetrate the plant. Brown spot markings or lines on one side of a mature apple are indicative of a spring hailstorm. Plants affected by salt stress are able to take water from soil, due to an osmotic imbalance between soil and plant. Poor growth and a variety of disorders such as leaf discolouration (chlorosis) can be caused by a shortage of one or more plant nutrients. Poor plant uptake of a nutrient from
Plant to plant communication via mycorrhizal networks help plants in mycorrhizal networks defend themselves against attack by pathogens or herbivores, and transferred nutrients can affect growth and nutrition. Results of studies which demonstrate these modes of communication have led the authors to hypothesize mechanisms by which the transfer of these nutrients can affect the fitness of the connected plants. Plants and fungi form mutualistic symbiotic relationships called mycorrhizae, which take several forms, such as arbuscular mycorrhizae (AM) and ectomycorrhizae (ECM), and are widespread in nature. Host plants provide photosynthetically derived carbohydrates to the mycorrhizal fungi, which use them in metabolism, either for energy or to increase the