Page 283 - PC2019 Program & Proceedings

PLANT CANADA 2019

P139. Evaluation of bottle and luffa gourds for commercial production in Canadian greenhouses
Arif, M.; P. Pauls
University of Guelph

The bottle gourd (Lagenaria siceraria) and luffa gourd (Luffa spp) are not cultivated in Canada, but there
is a demand from immigrants to Canada from warm regions of the World for these crops. We developed
hydroponic production systems in rockwool slabs for both bottle and luffa gourd in a greenhouse at the
University of Guelph. In addition, we screened 15 luffa and 5 bottle gourd varieties for their production of
commercial quality fruit. Large variation was noted for flower initiation in bottle gourds (43 – 67 days)
and luffa (45 – 50 days) after planting. In house pollination of luffa gourd by bees and of bottle gourd by
tomato hornworm moths was demonstrated. The first fruit pick in luffa and bottle gourds varieties was 60
– 98 days and 57 – 92 days respectively. The fruit was ready to pick in 10 – 12 days in bottle gourd and 6
– 7 days in luffa after pollination. Average fresh fruit weight ranged from 118 – 257 grams in luffa and
760 – 1243 grams in bottle gourd varieties. The number of fruit per plant ranged from 0 – 11 in the luffa
and 1-13 in the bottle gourd varieties over 2 months after planting. The initial results indicated that it
would be feasible to establish commercial production of these crops in Ontario greenhouses.

Muhammad Arif (marif@uoguelph.ca)

TOPIC 17: Mineral Nutrition (Posters P140-P142)

P140. Towards low-input production of subirrigated chrysanthemums: Phosphorus acquisition and
internal utilization efficiencies in two contrasting cultivars
Flaherty, E.; B. Shelp
University of Guelph

Greenhouse floriculture operations pose significant environmental risk due to extensive inputs of
fertilizer, especially N and P. Recent evidence shows that N and S use efficiencies are improved in
subirrigated, potted, disbudded chrysanthemums by supplying a moderate level of the respective nutrient
during vegetative growth, and removing the entire nutrient suite at the onset of reproductive growth,
without adverse effects on plant quality. Here, a split-plot experiment was conducted with plants grown
on four P regimens (2.6 mM P supplied during vegetative and reproductive stages, and 2.6, 1.95 or 1.3
mM P supplied during vegetative stage only) as the main plot and two cultivars (‘Olympia’ and
‘Covington’) as the sub-plot. Market quality plants with sufficient tissue-P were produced, even when P
delivery was reduced by approximately 75% over the crop cycle, compared to industry standards. The
primary mechanism for sustaining plant growth with decreasing Pi delivery was improved acquisition
efficiency, although some changes in internal P utilization efficiency were evident, including the
remobilization of both organic-P and inorganic-P during inflorescence development. Differences in
biomass yields, tissue-P concentrations, content-based P use efficiency with constant P acquisition, and
uptake- versus remobilization-based P supply for inflorescence growth established that ‘Olympia’ has a
greater internal P utilization efficiency than ‘Covington’. This modified subirrigation practice could lay
the foundation for low-input production of floricultural crops.

Edward Flaherty (eflahert@uoguelph.ca)

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