Macrophomina phaseolina is a soil-borne, plant pathogenic fungus that causes a variety of diseases in more than 500 plant species, including cotton. In the past, cotton cultivation in Israel was based on Acala-type (Gossypium hirsutum) cultivars. During the past 20 years, because of global economic changes, cotton cultivation in Israel shifted to Extra Long Staple (ELS) Pima-type (G. barbadense) cultivars that generated higher economic value to growers. Plant mortality caused by Macrophomina was known to affect Acala-type cultivars, however, disease severity appears to be greater in the Pima-type cotton. It seems that the pathogen can penetrate the plants and co-exists with it. Disease symptoms will appear only after the plant is exposed to heat or drought stress. Fungicides applied through the drip-irrigation system would have limited efficacy because cotton is typically seeded in two rows per bed, toward the edges, yet the drip irrigation pipe is placed in the middle of the bed. Also, the pathogen could be expected to be unaffected at soil depths where a fungicide cannot reach. Irrigation, water quantities and their timely application are key factors in cotton plant development and can affect not only yield and fiber quality but also disease incidence and severity. Indeed, during the summer of 2018, a leading cotton grower demonstrated that carefully planned and conducted irrigation and proper insect management to minimize stress prevented damage from Macrophomina. Monitoring the dynamics of disease progress is problematic in cotton where walking in the mature field is almost impossible. Applications of remote-sensing technologies can provide real-time, accurate estimations of disease location and progress in large fields throughout the growing season.
Macrophomina phaseolina is a soil-borne, plant pathogenic fungus that causes a variety of diseases in more than 500 plant species, including cotton. In the past, cotton cultivation in Israel was based on Acala-type (Gossypium hirsutum) cultivars. During the past 20 years, because of global economic changes, cotton cultivation in Israel shifted to Extra Long Staple (ELS) Pima-type (G. barbadense) cultivars that generated higher economic value to growers. Plant mortality caused by Macrophomina was known to affect Acala-type cultivars, however, disease severity appears to be greater in the Pima-type cotton. It seems that the pathogen can penetrate the plants and co-exists with it. Disease symptoms will appear only after the plant is exposed to heat or drought stress. Fungicides applied through the drip-irrigation system would have limited efficacy because cotton is typically seeded in two rows per bed, toward the edges, yet the drip irrigation pipe is placed in the middle of the bed. Also, the pathogen could be expected to be unaffected at soil depths where a fungicide cannot reach. Irrigation, water quantities and their timely application are key factors in cotton plant development and can affect not only yield and fiber quality but also disease incidence and severity. Indeed, during the summer of 2018, a leading cotton grower demonstrated that carefully planned and conducted irrigation and proper insect management to minimize stress prevented damage from Macrophomina. Monitoring the dynamics of disease progress is problematic in cotton where walking in the mature field is almost impossible. Applications of remote-sensing technologies can provide real-time, accurate estimations of disease location and progress in large fields throughout the growing season.