b'that appears translucent. Jelly end rotbreakdown is soft, jelly-like and slight-lywatery.Fusariumcaninfectjellyendsandappearlikedryrot.Theaffectedareamayextenduptoaninch (2.5 cm) or more from the stemend. As the tubers age or dry out, theFigure 6. affectedtissuedehydrates,shrivels,turnslightbrownandpapery.Heat Figure 10.stress can also stimulate growth of lat-eral buds, resulting in protruding eyesor knobs (Figure 8). HeatsproutsandchainingoftubersareanoutcomeofrenewedgrowthFigure 7. following a stress period. Heat sprouts(Figure 9) grow from stolons or tubersand will grow above ground into leafy Figure 11.stems (figure 10) or below ground asstolons(Figure11).Tuberchaining(Figure 12) can occur when stolons setmultipletubersononestolon.Varieties with short dormancy seem toFigure 8. be more prone to develop heat sproutsand chaining of tubers. This can result Figure 12.indormancybeingbrokencausingtuberstosproutpriortoharvest.Storing these potato tubers can be dif-ficult, as they are physiologically oldandwilloftendevelopsecondarytubers in storage (Figure 13). Potato second growth is a difficult dis-order to avoid because of the strongenvironmentalinfluenceonplantgrowthanddevelopment.Tomini-mize second growth, look for varietiesthatarelesspronetohavesecondFigure 9. growth and try to maintain ideal con- Figure 13.6). Tubers with pointy-ends, generally ditionsforuniformplantandtuber moisturetomeetcropdemand.thosereceivingtheearlybulking growth.Culturalmanagementprac- Irrigation can be used to cool the soil,stress,maydevelopjellyendrot tices may include promoting uniform but do not overwater because this can(Figure 7), or an accumulation of sug- stands, ensuring adequate plant nutri- leadtolenticelenlargementandars in the stem end rather than starch tionandpromotinguniformsoil pathogen entry into tubers. SEPTEMBER/OCOTBER 2020 POTATO GROWER 13'