Seasonal Trends of Total Nonstructural Carbohydrates in Lindheimer Pricklypear (Opuntia lindheimeri)

Abstract

Pricklypear (Opuntiaspp.) is a major constraint to rangeland livestock production in several resource areas of Texas. The phenological and physiological stages of pricklypear have heretofore been ignored in relation to timing of herbicide applications. The phenology, percent total nonstructural carbohydrates (TNC), and water content in Lindheimer pricklypear (Opuntia lindheimeriEngelm. # OPULI) were monitored biweekly for 2 yr in the southern Rolling Plains of Texas. TNC in cladophylls, crowns, and roots declined sharply from bud break (late March to late April) through the period of rapid development of new cladophylls and fruits, with minimum levels occurring during mid-July to early August. This depletion period coincides with the period when control has traditionally been attempted with broadcast applications of translocated herbicides with erratic results. Replenishment of TNC in cladophylls and basal crowns occurred during August through March or mid-April; major increases in root TNC occurred from early autumn through midwinter. Application of herbicide in late summer, autumn, or winter when TNC is being replenished in organs bearing meristematic tissue may be more effective for pricklypear control if the herbicide is translocated with photosynthates.

Carbon Relations of Flowering in a Semelparous Clonal Desert Perennial

“…Also, C0 2 exchange was measured for the inflorescence, whose contribution to its own carbon needs are frequently overlooked, but which can be significant , Williams et al 1985. Carbohydrate reserves support intensive flowering periods in arctic and alpine plants (Fonda andBliss 1966, Shaver andBillings 1976), crop plants (Sanz et al 1987), grassland plants (Menke and Trlica 1981), and desert plants (Potter et al 1986). Therefore, total nonstructural carbohydrate (TNC) levels were monitored to assess the contribution of stored carbon to production of the inflorescence.…”

Herbicidal Control of Pricklypear Cactus in Western Texas

“…New cladophylls were fully expanded and fruits were dropping at time of October 1982 treatments. Based on our data for Lindeheimer pricklypear (Potter et al 1986), we presumed that photosynthates were being replenished in pricklypear roots, crowns, and mature cladophylls when treatments were applied in December 1981, August 1982, and October 1982 and that photosynthates were being depleted (translocated upward) from these structures at treatment in June 1982. Soils were relatively dry when herbicides were applied in June, August, and October at San Angelo and in August at Coleman, but conditions were believed to be favorable for pricklypear growth at all treatment dates (Table 1) Phytotoxicity of the herbicide mixture to pricklypear was not fully manifested until 3 years after treatment (Fig.…”

“…These data are not conclusive, but suggest that populations of Lindheimer and Edwards pricklypear at San Angelo and pricklypear hybrids at Coleman were most susceptible to late summer and autumn applications of 2,4,5-T + picloram, and that the pricklypears were least susceptible to late spring applications. We propose that the apparent increased control after late summer and autumn treatments may be associated with greater translocation of herbicide into plant structures bearing perennating buds (crowns and mature cladophylls) during subsequent months, and that the decreased control following spring applications was associated with upward translocation of herbicides into new cladophylls and fruits (Potter et al 1986). Additional research is needed to substantiate this hypothesis and to definitively bracket the period(s) of greatest susceptibility of pricklypear to picloram.…”

“…We hypothesized that herbicide applications during late summer, autumn, and winter might kill more Lindheimer pricklypear (0. lindheimeri Engelm.) than late spring or early summer applications because photosynthates are replenished in the roots, crowns, and mature cladophylls during late summer through winter (Potter et al 1986). Photosynthates from these stuctures are translocated upward into new cladophylls and fruits during spring through midsummer.…”

On the possible role of nonreproductive traits for the evolution of unisexuality: Life‐history variation among males, females, and hermaphrodites in Opuntia robusta (Cactaceae)

“…The production of vegetative buds in Opuntia spp. is annual and follows a seasonal pattern similar to that of flowering buds (e.g., Potter, Petersen, & Ueckert, ). Thus, the above values indicate that unisexuality accelerates sexual maturation.…”