Studies On Brassica Cyst Nematode Heterodera Cruciferae

Observations on the Development of the Brassica Cyst Eelworm

“…Cyst populations from soil samples showed no consistent increase under brassica crops (cf. Sykes and Winfield, 1966).…”

“…Brassica cyst eelworm {Heterodera cruciferae Frankhn) is widely distributed in Lincolnshire and Bedfordshire (Sykes and Winfield, 1966;Winfield et al, 1970). It also occurs in fields intensively cropped with brassicas in South Wales, associated with poor growth and red discoloration of the leaves of brassica seedlings and with excessive development of lateral roots.…”

Pathogenicity and Host–Parasite Relationships of Heterodera cruciferae in Cabbage

“…Results also suggested that these infections support successful cyst nematode reproduction that increases the soil inoculum for the next growing season. The results obtained also showed that the threshold damage of cabbage by H. cruciferae (1.50 units of eggs and J2/cm-^ of soil) was significantly lower than those reported by McCann (18) in cabbage (40 cysts/100 cm' of soil) or those reported in cauliflower (25 units of eggs and J2/cm-' of soil) (33). The lower tolerance limits described above suggested that H. cruciferae has the potential to severely damage cabbage under Mediterranean environmental conditions, particularly during warm autumn growing seasons; as for other cyst nematodes, warm temperatures increase its development and reproduction (34).…”

“…Although damage caused by the cabbage cyst nematode H. cruciferae to cabbage is known in several growing areas such as Europe, California, Russia, South Australia, and Turkey (4,6,9,11,19,29), some controversy exists regarding the pathogenicity, threshold levels, and host-parasite relationships on cabbage. Some authors have not considered H. (18,33). The sugar beet cyst nematode H. schachtii has also been reported as damaging cabbage and occurring together in the same fields with H. cruciferae (28).…”

Hatching from cysts and egg sacs of Heterodera cruciferae and effects of temperature on hatching and development on oilseed rape

“…Such persistence is likely, in turn, to result in a very wide distribution of these cyst nematodes, especially in areas where agricultural crops capable of acting as hosts are grown. Heterodera cruciferae is, in fact, found very frequently (in 70% of fields or more) in vegetable brassica growing areas such as Lincolnshire (Sykes & Winfield, 1966), Bedfordshire (Winfield, Coppock & Whitlock, 1970) and South Wales (Lewis, 1971) but little is reported of its biology. Sykes & Winfield (1966) related pre-cropping nematode numbers to damage in a crop of cauliflowers and Lewis (1971) made sequential plantings of cabbage seedlings throughout the year to measure development rates : by recording the time taken to produce eggs containing juveniles, she was able to show that two generations can occur between April and September and perhaps a third generation between September and November.…”